Intercomparison of ATMOS, SAGE II, and ER-2 observations in Arctic vortex and extra-vortex air masses during spring 1993

We have compared measured abundances of NOy, O-3, H2O, CH4, HCl, and N2O fr om ATMOS and aerosol from SAGE II from inside and outside the Arctic vortex with in situ observations from the SPADE aircraft campaign in April/May 19 93. When the distinction between vortex and extra-vortex air is taken into account, SPADE measurements of NOy, O-3, H2O, CH4, HCl, and aerosol abundan ces, correlated with [N2O], demonstrate excellent agreement with ATMOS and SAGE II data. Observations of low [HCl] and high [ClNO3] inside the vortex by ATMOS and low [HCl] in vortex fragments by ALIAS suggest that vortex-inf luenced air masses maintained unusually high levels of [ClNO3] throughout s pring 1993.